In a scrappy first half with few chances, the Brazilian outfit managed to edge into the lead in front of their home fans just before the break thanks to a Marco Antonio header.

Chances came and went for the hosts but they had to settle for a one-goal advantage to take into their second-leg clash in Colombia on November 16.

In the 36th minute, Gremio earned a corner and Ze Roberto's in-swinging cross was flicked on at the near post by a Millonarios defender to Antonio, who was unmarked at the back post and completed a simple header to score.

The home team's best chance to extend their lead came in the 76th minute when Leo Gago hit the post, while substitute forward Andre Lima had a goal ruled out for offside in the final minute of the match.